Hijri year

The Hijri year (Arabic: سَنة هِجْريّة) or era (التقويم الهجري at-taqwīm al-hijrī) is the era used in the Islamic lunar calendar. It begins its count from the Islamic New Year in which Muhammad and his followers migrated from Mecca to Yathrib (now Medina) in 622 CE. This event, known as the Hijrah, is commemorated in Islam for its role in the founding of the first Muslim community (ummah).

In the West, this era is most commonly denoted as AH (Latin: Anno Hegirae /ˈænoʊ ˈhɛdʒɪriː/, 'in the year of the Hijra') in parallel with the Christian/Common (AD/CE) and Jewish eras (AM) and can similarly be placed before or after the date. In predominantly Muslim countries, it is also commonly abbreviated H ("Hijra") from its Arabic abbreviation hāʾ (هـ). Years prior to AH 1 are reckoned in English as BH ("Before the Hijrah"), which should follow the date.[1]

A year in the Islamic lunar calendar consists of twelve lunar months and has only 354 or 355 days in its year. Consequently its New Year's Day occurs ten days earlier each year relative to the Gregorian calendar. The year 2023 CE corresponds to the Islamic years AH 1444 – 1445; AH 1445 corresponds to 2023 – 2024 in the Common Era.[lower-alpha 1]

Definition

The Hijri era is calculated according to the Islamic lunar calendar, whose epoch (first year) is the year of Muhammad's Hijrah, and begins on the first day of the month of Muharram (equivalent to the Julian calendar date of July 16, 622 CE).[2] [lower-alpha 2]

The date of the Hijrah itself did not form the Islamic New Year. Instead, the system continues the earlier ordering of the months, with the Hijrah occurring around the 8th day of Rabi al-Awwal, 66 days into the first year.

History

Predecessors

By the age of Muhammad, there was already an Arabian lunar calendar, with named months. Likewise, the years of its calendar used conventional names rather than numbers:[3] for example, the year of the birth of Muhammad and of Ammar ibn Yasir (570 CE) was known as the "Year of the Elephant".[4] The first year of the Hijra (622-23 CE) was named the "Permission to Travel" in this calendar.[3]

Establishment

17 years after the Hijra,[3][5] a complaint from Abu Musa Ashaari prompted the caliph Umar to abolish the practice of named years and to establish a new calendar era. Umar chose as epoch for the new Muslim calendar the hijrah, the emigration of Muhammad and 70 Muslims from Mecca to Medina.[6] Tradition credits Othman with the successful proposal, simply continuing the order of the months that had already been established by Prophet Muhammad, beginning with Muharram, as there was no set order of months during the pre-Islamic era (Age of Ignorance - Jahiliya). Adoption of this calendar was then enforced by Umar.[7]

Formula

Different approximate conversion formulas between the Gregorian (AD or CE) and Islamic calendars (AH) are possible:[8][9][10]

AH = 1.030684 × (CE − 621.5643)
CE = 0.970229 × AH + 621.5643

or

AH = (CE − 622) × 33 ÷ 32
CE = AH × 32 ÷ 33 + 622

Given that the Islamic New Year does not begin January 1 and that a Hijri calendar year is about 11 days shorter than a Gregorian calendar year,[11][lower-alpha 3] there is no direct correspondence between years of the two eras. A given Hijri year will usually fall in two successive Gregorian years. A CE year will always overlap two or occasionally three successive Hijri years. For example, the year 2008 CE maps to the last week of AH 1428,[13] all of 1429,[14] and the first few days of 1430.[15] Similarly, the year 1976 CE corresponded with the last few days of AH 1395, all of 1396, and the first week of 1397.

Months

The Hijri year has twelve months, whose precise lengths vary by sect of Islam. Each month of the Islamic calendar commences on the birth of the new lunar cycle. Traditionally this is based on actual observation of the moon's crescent (hilal) marking the end of the previous lunar cycle and hence the previous month, thereby beginning the new month. Consequently, each month can have 29 or 30 days depending on the visibility of the moon, astronomical positioning of the earth and weather conditions. However, certain sects and groups, most notably Bohras Muslims namely Alavis, Dawoodis and Sulaymanis and Shia Ismaili Muslims, use a tabular Islamic calendar in which odd-numbered months have thirty days (and also the twelfth month in a leap year) and even months have twenty nine.

Notes

See List of Islamic years#Modern.
This date is based on a reconstruction of the early Islamic calendar and, assuming that intercalation was performed before 10 AH, an earlier date in April is also possible.
As the mean duration of a tropical year is 365.24219 days, while the long-term average duration of a lunar year is 354.36707 days,[12] the average lunar year is (365.24219 − 354.36707 ≈) 10.88149 days shorter than the average solar year, causing months of the Hijri calendar to advance about eleven days earlier relative to dates in the Gregorian calendar every calendar year. The precise number of days varies, depending on accumulated differences and potential for leap-years to happen at different times.

References

Registration locations, Government of Sharjah, archived from the original on 2 February 2017, retrieved 21 January 2017.
Thomann, Johannes. "Islamischer Kalender". Universität Zurich Universität Zürich Asien-Orient-Institut. Retrieved 11 April 2023.
Aisha El-Awady (2002-06-11). "Ramadan and the Lunar Calendar". Islamonline.net. Retrieved 2006-12-16.
Hajjah Adil, Amina, "Prophet Muhammad", ISCA, Jun 1, 2002, ISBN 1-930409-11-7
Hakim Muhammad Said (1981). "The History of the Islamic Calendar in the Light of the Hijra". Ahlul Bayt Digital Islamic Library Project. Retrieved 2006-12-16.
The Beginning of Hijri calendar – Paul Lunde, Saudi Aramco World Magazine (November/December 2005), retrieved 1/1/2019
Umar bin Al-Khattab (2002). "Islamic Actions and Social Mandates: The Hijri Calendar". witness-pioneer.org. Retrieved 2006-12-16.
Islamic and Christian Dating Systems
Clark, Malcolm (2013). Islam for dummies. Hoboken, N.J.: John Wiley & Sons. p. 489. ISBN 978-1118053966.
Hodgson, Marshall G. S. (1977). The venture of Islam conscience and history in a world civilization. Chicago: University of Chicago Press. p. 21. ISBN 0226346862.
Chisholm, Hugh, ed. (1911). "Hejira" . Encyclopædia Britannica. Vol. 13 (11th ed.). Cambridge University Press. p. 218.
P. Kenneth Seidelmann, ed. (1992). Explanatory Supplement to the Astronomical Almanac. p. 577. For convenience, it is common to speak of a lunar year of twelve synodic months, or 354.36707 days. (which gives a mean synodic month as 29.53059 days or 29 days 12 hours 44 minutes and 3 seconds)
""Islamic New Year Observed Today; President Airs Wish for Peace on Amon Jadid Exhorts Muslims to Assist in Nat'l Resurgence". Manila Bulletin. January 20, 2007.
"Islamic New year to be observed on 11th January". AAJ News. Aaj.tv. 2008-01-10. Archived from the original on 2018-12-22. Retrieved 2013-05-22.
"Visibility of Muharram Crescent 1430 AH". Islamic Crescents' Observation Project. Archived from the original on 2021-02-23. Retrieved 2018-12-21.